I was sent a refurbished Ipod nano 7gen by Apple to replace an Ipod that the play/pause button broke on, and I have been having a very similar problem with the both the voice-over and play pause freaking out at the same time.
I will be listening to a song and it will start randomly play/pausing, then the voice-over will start freaking out by listing the song that I'm listening too, start going through the other playlists on the ipod, start playing songs from a new playlist, start jumping back and forth between songs on the new playlist, all the while randomly starting the voice-over over and over again for each new song and playlist. It goes on indefinitely until I put the ipod in sleep mode. Most of the time I bring it back out of sleep it still wont function properly, but sometimes it will start working again if I let it sit for a few hours.
I have contacted apple support and the guy who helped me said that I could try doing a hard reset ,which didn't work, or restoring the ipod to factory settings through itunes. This worked the first time for 2 weeks of heavy use (pretty much 6hrs every day use), didn't work the second time, and worked the third time for one week of non use (I left the ipod on my table paused on a LONG song and watched to see if it had play/paused on its own or randomly changed songs, which it did not for a week of observation) followed by two days of moderate use (around 6hrs a day again, with each day being about three days apart). The second day it started to freak out again, so I left it in sleep mode for about 3hrs and then used it again and it stropped freaking out. The "second day" I'm referring to is the same day I'm typing this, so I haven't had a chance to see how long it will continue to work properly.
Now this wouldn't be so bad if it weren't for the fact that resetting my ipod to factory settings causes a disconnect error with my external hard drive every time, which requires me to unplug and plug back in my external hard drive each time for my computer to recognize it. I have no idea why this happens, but I do know it is a nuisance.
I have no lasting solution for anyone, everything I've done is just a temporary solution that doesn't fix the permanently.